Domiciliary immunisation for preschool child defaulters.

A selective domiciliary immunisation service has been introduced for preschool children living in the Central Manchester Health District. The service is provided for the children of parents who have given written consent for immunisation but have subsequently failed to bring their children to the clinic or their general practitioner''s surgery to start or complete the basic course of immunisation against diphtheria, tetanus, whooping cough, poliomyelitis, and measles. This failure has occurred despite at least two written invitations for each injection and several reminders from the health visitor. Many additional children have been protected by this scheme.     

Duration of effectiveness of pertussis vaccine: evidence from a 10 year community study

A 10 year study of whooping cough in a discrete general practice community was performed to assess longitudinally the efficacy of pertussis vaccine from one to seven years after immunisation. Of the 436 cases of whooping cough over 10 years, 326 occurred in children aged 1-7 years. The rate of immunisation was known for each cohort of children born during each year, and the attack rate of whooping cough was thus calculated for those immunised and unimmunised. The attack rates were highest in those cohorts exposed to the epidemics of 1977-9, 1981-3, and 1985-7. The efficacy of the vaccine was calculated as a percentage as (attack rate in unimmunised group—attack rate in immunised group) × 100/attack rate in unimmunised group. It fell from 100% in the first year to 46% in the seventh, being 84% in the fourth and only 52% in the fifth.Thus the pertussis vaccine or its schedule of use does not seem to provide sufficient herd immunity to prevent outbreaks of whooping cough. Matters might be improved if vaccination against pertussis were included in the preschool immunisation programme.     

Protection against pertussis by immunisation.

Review of all 126 children admitted to the communicable diseases unit with whooping cough during the epidemic in 1978 showed that two had received two doses of triple vaccine and only one had had full primary immunisation against the disease. None of these three children suffered complications of the disease. Of the 123 children who had not been immunised against pertussis, however, 66 had had one or more complications. In Birmingham the dramatic decline in immunisation against pertussis has been accompanied by a fall in acceptance rates for diphtheria and tetanus immunization. Nevertheless, of the 62 children aged over 1 year in this series, 41 had been so immunised. These findings suggest that the apparently positive decision by parents to omit pertussis immunisation was misplaced, since immunisation does protect against the more serious complications of the disease. Furthermore, there is no firm evidence that pertussis immunisation of children without specific contraindications is associated with serious adverse reactions.     

Whooping cough after stopping pertussis immunisation.

An epidemic of whooping cough occurred in a rural practice in Shetland, containing 144 children under 16. Before July 1974 all children were immunised against pertussis, but after that date immunisation was stopped. Of the 134 children studied, 93 had been immunised. Sixty-five of the children developed whooping cough. The incidence of infection was similar in those who had and had not been immunised. The incidence was also similar in those born before and after July 1974. There was no evidence to support the routine use of pertussis immunisation in rural Shetland.     

Natural course of 500 consecutive cases of whooping cough: a general practice population study.

OBJECTIVE--To describe the natural course of whooping cough. DESIGN--Observational study of a general practice population. SETTING--Discrete semirural East Midlands practice of 11,500 patients. SUBJECTS--500 consecutive cases of whooping cough diagnosed clinically during 1977-92. MAIN OUTCOME MEASURES--Incidence of vomiting, whooping, apnoea, admission to hospital, and complications; duration and frequency of paroxysms. Pattern of spread. RESULTS--The incidence in the practice population was 4347/100,000 population compared with a notification rate for England and Wales of 717/100,000. Most cases were relatively mild. 284 patients vomited after paroxysms, 242 whooped, and 57 had apnoea. Duration and frequency of paroxysms varied widely. Female and unimmunised patients suffered more severe disease. Bordetella was isolated from fewer immunised patients (24/96 v 63/122 unimmunised). Infection was usually spread through contacts with someone with clinical whooping cough. Five patients developed pneumonia, three of whom had been immunised. Three patients required hospital admission. CONCLUSIONS--Most cases of whooping cough are relatively mild. Such cases are difficult to diagnose without a high index of suspicion because doctors are unlikely to hear the characteristic cough, which may be the only symptom. Parents can be reassured that a serious outcome is unlikely. Adults also get whooping cough, especially from their children, and get the same symptoms as children. The difficulty of early diagnosis and probability of missed cases reinforces the need to keep the incidence low through immunisation in order to protect infants, who are the most vulnerable.     

Epidemiology of chickenpox in England and Wales, 1967-85

Routine sources of data on chickenpox morbidity and mortality in England and Wales were reviewed for 1967-85. Only two epidemics occurred, one in 1967 and one in 1980, both of which were immediately followed by two to three years of low incidence. The age distribution of the disease appears to be changing, with more cases now being reported in children aged 0-4 years. The number of deaths in adults have, however, increased, particularly those deaths that are associated with pneumonia and immunosuppression. At present in England and Wales more deaths are attributed to chickenpox than to whooping cough and mumps.Widespread use of selective immunisation against chickenpox might be justified in England and Wales, but before routine immunisation of the child population can be considered special surveys to determine the incidence and severity of chickenpox and the effect of the vaccine on the subsequent development of herpes zoster are needed as well as cost-benefit studies of immunisation.     

Growth retardation in weight and catch-up growth following infection by measles and whooping cough among babies of rural Zaire (Lake Tumba)

This study has shown that measles and whooping cough affect growth in weight among babies of rural Zaire (Lake Tumba). The average loss in weight due to measles, is more than twice the amount due to whooping cough. However, the time needed to regain the original growth channel after infection by measles, is about half the time needed to fully catch up after whooping cough. The amount of weight loss is proportional to the child's weight at the onset of the disease. There is no difference in the susceptibility to lose weight after measles or whooping cough, between boys and girls, nor between Oto and Twa. This study has also shown that the effect of measles and whooping cough on the growth in weight, is independent of the season of the hear, although the incidence of these diseases showed a significant seasonal pattern. Finally, this study gives evidence for the fact that the incidence of weight loss one month after the onset of measles or whooping cough is age-related.     

The protective effect of immunisation against diphtheria, pertussis and tetanus (DPT) in relation to sudden infant death syndrome

Epidemiological evidence indicates infants immunised against diphtheria, pertussis and tetanus (DPT) are at decreased risk of sudden infant death syndrome (SIDS). Asymptomatic whooping cough and pyrogenic toxins of Staphylococcus aureus have been implicated in the aetiology of SIDS. The objectives of the present study were: (1) to determine if the DPT vaccine induced antibodies cross-reactive with the staphylococcal toxins; (2) to determine if antibodies to the pertussis toxin (PT) and the staphylococcal toxins were present in the sera of women during late pregnancy; (3) to examine the effects of infant immunisation on levels of antibodies to PT and the staphylococcal toxins; (4) to assess the effects of changes in immunisation schedules in the UK on the incidence and age distribution of SIDS. Enzyme-linked immunosorbent assays (ELISA) were used to measure binding of rabbit or human IgG to the DPT vaccine, PT, toxic shock syndrome toxin-1 (TSST-1) and staphylococcal enterotoxins A (SEA), B (SEB) and C (SEC). Neutralisation activity of anti-DPT serum was assessed by a bioassay for induction of nitric oxide from human monocytes by the staphylococcal toxins. Anti-DPT serum bound to the DPT vaccine, PT and each of the staphylococcal toxins. It also reduced the ability of the four toxins to induce nitric oxide from monocytes. In pregnant women, levels of IgG to PT, SEC and TSST-1 decreased significantly in relation to increasing weeks of gestation while antibodies to SEA and SEB increased. In infants' sera there were significant correlations between levels of IgG bound to DPT and IgG bound to PT, TSST-1 and SEC but not SEA or SEB. Antibody levels to the toxins in infants declined with age; sera from infants < or = 2 months of age had higher levels of IgG bound to the toxins than those older than 2 months. This pattern was observed for infants whose immunisation schedules began at 2 months of age or 3 months of age. The decrease in IgG bound to the toxins was, however, less for those immunised at 2 months. The decrease in SIDS deaths after the change in immunisation schedules was greatest in the 4-6-month age range. While DPT immunisation might prevent some unexplained infant deaths due to asymptomatic whooping cough, these data indicate that immunisation with DPT also induces antibodies cross-reactive with pyrogenic staphylococcal toxins implicated in many cases of SIDS. Passive immunisation of infants who have low levels of these antibodies might reduce further the numbers of these infant deaths.     

Attack rates of notified whooping cough in immunised and unimmunised children.

The incidence of whooping cough among immunised children under the age of six and among children of the same age who were not fully immunised was ascertained by analysing whooping-cough notifications from several health authorities. In the first three years of the study the results showed that attack rates were much higher in children who were not fully immunised than in those who were. This finding suggests that current vaccines provide young children with substantial protection against whooping cough.     

Study of children not immunised for measles.

The results of a survey of the 165 children born in 1980 in a population served by a health centre showed that 42 were not immunised against measles. The reasons for non-immunisation included 18 refusals (usually on the grounds of incorrect contraindications) and 19 defaulters (where the children were not brought for immunisation). Twenty of the children had contracted measles by March 1984. Among the 19 defaulters 12 had been registered with the health centre since age six months or under. Their average number of consultations a year was four. None of the 42 children had Department of Health and Social Security recommended contraindications to measles immunisation.     

Impact of whooping cough on patients and their families.

The effects of whooping cough were studied in 21 children admitted to hospital with the disease and in their families. The illness caused considerable distress to both child and family. Parents suffered especially from fears for the life and health of their child and from serious loss of sleep. Two months after admission the child''s behaviour was still disturbed, but in most cases the rest of the family had returned to normal. There was much misunderstanding and misinformation about whooping cough among both parents and doctors.     

Injury by hypertonic phosphate enema.

Over a 2-year period 67 strains of Bordetella pertussis were identified in 231 single specimens of nasopharyngeal secretions submitted from patients suspected to have whooping cough in the National Capital Region; 89.5% of the identifications were made by culture. Serotype 1,3 was predominant. At least 75% of the patients with bacteriologically confirmed whooping cough had not been fully immunized. There was no evidence that adenoviruses or other viruses played any important etiologic role in the 204 cases of whooping cough or whooping cough syndrome studied virologically.     

Study of intellectual performance of children in ordinary schools after certain serious complications of whooping cough. Swansea Research Unit of the Royal College of General Practitioners.

In a case-control study 27 index children from ordinary schools who had had convulsions or apnoea as a complication of whooping cough about eight years previously were compared with 27 children who had never had whooping cough and 15 who had had whooping cough without complications. Other factors likely to cause intellectual impairment after conception were considered. The index group had a significantly lower median intelligence quotient and poorer school attainment than either of the control groups. The results support the hypothesis that convulsions or apnoea as a complication of whooping cough may be associated with subsequent intellectual impairment.     

Whooping cough in adults.

During the 1970s whooping cough returned in Sweden after an absence of more than 10 years and is now seen in all age groups, During a three-year period 174 adults with culture-verified whooping cough were identified in Gothenburg. Most of the patients had typical symptoms with whooping attacks and often vomiting. The disease was long lasting but complications were rare. Physicians should be aware that whooping cough may occur in adults, since adults may be an important source of infection for infants and erythromycin given in the catarrhal phase may modify the clinical course.     

Effect of vaccination on severity and dissemination of whooping cough.

A study was undertaken in general practice to clarify those factors, especially vaccinations, that influence the clinical picture and infectivity of whooping cough in the community. Although the range of the disease encountered was fairly mild, its duration was notable (mean +/- SD 50.9 +/- 32.1 days). By using multiway contingency table analysis it was found that in the more severe cases of whooping cough vaccination significantly shortened the illness (p less than 0.005) and reduced the number of coughing spasms (p less than 0.025). The protective effect of the vaccine was most notable in modifying infectivity within the family: 19% of vaccinated family contacts of index patients in whom the disease had been confirmed bacteriologically developed the disease when exposed to it compared with 72% of non-vaccinated contacts (p less than 0.001). These results show that whooping cough vaccination modifies the clinical illness and offers a worthwhile degree of protection to children exposed to the disease.     

Surface-exposed antibody-accessible outer membrane proteins of Bordetella pertussis

The convalescent sera from a patient recovered from whooping cough were used to identify the surface-exposed antibody-accessible outer membrane proteins (OMPs) of Bordetella pertussis. The results indicated that the 69,000 OMP, the 40,000 porin, agglutinogens 2 and 3, and a number of presently unknown OMPs were exposed on the surface. The importance of these surface-exposed antigens in the protection against whooping cough is discussed.     

Whooping-cough vaccine. Statement by Joint Committee on Vaccination and Immunization of the Central Health Services Council and the Scottish Health Service Planning Council.

In 1974 it was recommended that pertussis vaccine should continue to be offered in a triple vaccine together with diphtheria and tetanus vaccines. Further data on the prevalence of whooping cough and the incidence of adverse reactions have shown no reason to change this policy; the hazard of whooping cough remains greater than that of immunization.     

Inhibiting effect of ADP-ribosylation by pertussis toxin on passive transport of Ca2+ into the cell membrane of porcine myometrium]

ADP-ribosylation by whooping cough toxin of protein components of inside-out oriented vesicles of pig myometrium plasma membranes under conditions of their depolarization results in significant inhibition of passive transport of Ca2+ ions. The inhibiting effect is dose- and time-dependent. rho-Chloromercuribenzoate (0.5 mM) blocks the effect of whooping cough toxin, no such effect on Ca2+ transport being observed in control preparations.     

Etiology, clinical manifestations, and epidemiology in community-acquired respiratory infection in children in the Khabarovsk region

Clinico-epidemiological analysis and etiological verification of the outbreak of respiratory infection among school children in a rural district of the Khabarovsk territory, registered in spring 1997, were made. According to clinical signs, one-third of the patients had whooping cough, while the rest of the children exhibited the signs of respiratory infection with the symptoms of longering bronchitis. A half of the children had not been vaccinated against whooping cough, as they had been given injections of adsorbed DT vaccine with reduced antigen content. Etiologically, the diagnosis of whooping cough was confirmed in 57% of the patients with 47.4% of them having Bordetella pertussis monoinfection and 52.6% having mixed infection, mainly in combination with chlamydiosis. Whooping cough took an abnormal course under these circumstances. Treatment with erythromycin produced a good effect.     

Intensity of the epidemic process of whooping cough under conditions of mass immunization over a period of many years

On the basis of analysis of whooping cough incidence in 1959 to 1975 in Moscow the authors present characteristics of the epidemic process under conditions of planned many-year immunization of children against this infection. Whooping cough morbidity proved to undergo significant changes-from sharp falls the first 8 years of immunization to a relative stabilization with a gradual reduction the last 5 years. Marked seasonal and periodic elevations persist against the background of reduction of morbidity. Preschool- and schoolchildren are equally involved in the epidemic process; the most frequently involved are nonvaccinated children aged 1 year and 4 to 10 years, which lost postvaccinal immunity. Further reduction of the severity of whooping cough and increase in the number of unimanifested forms of the infection was noted. This was apparently connected not only with immunization, but also with the reduction of the virulence of H. pertusis detected in studying the cultures isolated in Moscow from 1967 to 1974. The intensity indices of the epidemic process in whooping cough pointed to the necessity of using a more effective vaccine for the protection of children from whooping cough, despite the noted reduction of morbidity, and diminished severity of the course of the disease, and of the causative agent virulence.